Suspended working platform unit

ABSTRACT

961,811. Workmen&#39;s staging in tanks. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. Feb. 26, 1963 [Feb. 28, 1962], No. 7700/63. Heading E1S. A workmen&#39;s platform 4 for use in a tank &amp;c. is mounted on a pivot 5 on a vertical shaft 1 and held horizontally by a stay 6 engaging a hook 9 on the shaft which is rotatably mounted in a carrier 2 in the tank roof 3. The shaft is suspended by a rod 10 engaging in plates 11 on a plate 12 rotatable on a bearing 22 on the carrier 2. The platform is adapted to be inserted through an opening in the tank roof for suspension from the carrier 2.

May 18, 1965 H. P. KLEISS 3,183,997

SUSPENDED WORKING PLATFORM UNIT Filed Feb. 7, 1963 2 Sheets-Sheet 1INVENTORI FIG 2 HENDRICUS P. KLEISS HIS ATTORNEY May 18, 1965 H. P.KLEISS 3,183,997

SUSPENDED WORKING PLATFORM UNIT Filed Feb. '7, 1963 2 Sheets-Sheet 2INVENTOR:

HENDRICUS P. KLEISS BY: My) @MVZv HIS ATTORNEY United States Patent "6)9 2 Claims. ((31. 182-82) The invention relates to a suspended workingplatform unit for carrying out operations in tanks, holds, bunkers andsimilar spaces. In order to carry out certain operations, such as theinspection and painting of the inner walls of tanks, it is oftennecessary to erect scaffolding in the tank in order to make the top partaccessible to the workmen. The assembly and subsequent dismantling ofthis scaffolding, which may be designed in the form of suspended workingplatform units, is a time-consuming task. This drawback occurs inparticular when the scaffolding has'to be made up of numerous parts asin spaces which are only provided with narrow access openings. Anexample of such difficulty accessible spaces is afforded by the tanks oftankers. It is the object of the invention to provide a suspendedworking platform unit of a simple design which can be rapidly arrangedin a tank or another space.

The suspended working platform unit according to th invention ischaracterized in that it consists of a shaft to be hung vertically, thetop part of which shaft can be secured in a carrying member which can bepositioned above an opening in the tank roof, and the bottom part ofwhich shaft is provided with a platform which in the horizontal positioncan be fixed to the shaft.

A unit of this type can be lowered through a relatively narrow openinginto the tank, but when it is secured in the operating position itcovers a large operating area. The suspended working platform unit ispreferably designed with a platform which can be moved hingeably in avertical plane so that the suspended working platform unit can bereadily inserted as a whole in an oblong shape.

By rotatably suspending the shaft in the carrying member the area of thetank which can be covered by the platform is substantially increased,but should it still be impossible to reach the Whole surface which is tobe treated in the tank the suspended working platform unit can beshifted in a simple and rapid manner to an adjoining surface.

An embodiment of a suspended working platform unit according to theinvention will now be described with reference to the accompanyingdrawing. drawing:

FIG. 1 is a lateral view of the suspended working platform unitsuspended in operating position.

FIG. 2 is a top plan View of the carrying member as shown in FIG. 1.

FIG. 3 is a diagram of a lateral view of the suspended Working platformunit being introduced into a tank of a tanker.

Referring to FIG. 1, the top part of a shaft 1 is secured in a carryingmember 2 mounted above an opening in a cover plate 3 of the tank. At thebottom part of the shaft 1 is arranged a platform 4 consisting of atubular Referring to the 2 frame and plates and so secured at one end tothe shaft 1 by means of a hinge 5 as to be rotatable in a verticalplane. The platform 4 can be fixed in a horizontal position by means ofa connecting element 6 one end of which is joined to the platform 4 bymeans of a hinge 7, the other end being provided with an eye. 8 fittingdetachably around a hook 9 of the shaft 1.

The shaft 1 is suspended in the carrying member 2 3,183,997. PatentedMay 18, 1965 from a detachable tumbler bolt 10 which is insertedtransversely through the end of the shaft 1 projecting beyond thecarrying member 2 and secured therein by means of a rotatable retainingmember 23. A liner 25 is provided in the shaft 1 around the bolt 10. Inorder to lower and hoist the shaft 1 with the platform 4, a hook 30secured to a rope 31 may be fastened around the liner 24 (as will beseen from FIG. 3). After the bolt 10 has been removed from the shaft 1the latter can be lowered by means of the carrying member 2. The bolt 10rests in oppenings of supporting plates 11, the latter being secured toa plate 12 which rotatably mounted on the carrying member 2 via a slipring 22, so that the entire assembly of the platform 4, the shaft 1, thebolt 10, the supporting plates 11 and the plate 12 is rotatable relativeto the fixed carrying member 2. Instead of the slip ring 22 use may alsobe made of a ball bearing or the like. The assembly may be rotated byexerting a tangential force on the end of the bolt 10, for instance by aworkman on the roof of the tank. If necessary, the workman can revolvehimself on the platform 4 by leaning against reinforcement beams, etc.of the tank. The rotatable plate 12 is provided with an eye 13 having anopening 14 which is, in various positions of the plate 12, above one ofthe openings 15 of the top flange plate 16 of the carrying member 2.When a retaining pin is inserted through superposed openings 14 and 15the rotatable plate 12 and the parts connected thereto can be fixed in agiven angular position relative to the tank.

The dimensions of the platform 4 should be so adapted to the size of theopenings present in the tank deck that the suspended working platformunit can be moved into and out of the tank space. In general, this isthe case when the platform 4 is so designed that in the best position itcan still be slid through the largest access opening of the tank.

The openings in the tank deck in which the suspended working platformunit is suspended may, however, be much smaller than the largest accessopening; the suspension openings need only be large enough to make itpossible for the carrying member 2, which is narrow compared to theplatform 4, to be placed on the cover plate 3. Such openings are usuallypresent in tanks of tankers.

If necessary, the platform 4 may be provided with a detachable guardrail 21.

In order to use the suspended working platform unit the carrying member2 is secured as a separate part above the suspension opening of the tankby means of the bolts already provided for closing the opening. Theconnecting element 6 detached from the shaft 1 is rotated into aposition alongside the platform 4; the latter is capable of rotatingfreely about the hinge 5, so that the suspended working platform unit,when suspended from the shaft 1, occupies a more or less extendedposition. In this position the platform is now placed above an accessopening 17 of a tank 20 and then passed into the tank 20 through thisopening 17 (see FIG. 3). The suspended working platform unit is loweredonto the bottom of the tank 24) or to a reinforcement frame which ishigher than the bottom, where a workman situated at thispoint fixes theplatform4 to the shaft 1 in a horizontal position by engaging theconnecting element 6 around the hinge 7 and booking it onto the shaft 1.

The suspended working platform unit is now lifted and suspended by meansof the bolt 10 from the shaft 1 in the carrying member 2. Workmen canreach the platform 4 by means of a rope ladder from the bottom of thetank or from reinforcement beams therein; from the platform they cancarry out work on the inside walls of the tank 29.

Since the shaft 1 is made rotatable in the carrying member 2, a largepart of the inner surface of the tank 20 can be covered by the platform4 without the necessity of suspending the unit elsewhere. If, however,the area to be Worked withinthe same tank 20 is greater than thatcovered by the rotatable platform the unit can be placed in a simplemanner in a suspension opening situated further away; this can be doneby pulling the bolt out of shaft 1, loweringthe shaft 1 with theplatform 4, removing the carrying member 2 and securing it above the newsuspension opening, again raising the shaft 1 in the carrying member 2and inserting the bolt 10 through the top of the shaft 1. The unit isremoved from the tank in the same way as it is introduced therein, butthe necessary steps are then taken in the reverse order.

Although in the embodiment the starting point was a suspended workingplatform unit of which the shaft 1 is secured in the carrying member 2so as to rotate and permit removal, this is not essential. 'If, however,the shaft is arranged rigidly in the carrying member the latter cannotbe separately secured to the tank roof from outside but should beinserted together with the shaft through the suspension opening frominside the tank. In order to introduce the carrying member it is thennecessary for this opening to be somewhat larger than when the carryingmember is designed as a separate member. After the carrying member hadbeen inserted in the opening auxiliary plates are secured above theopening on the tank deck on either side of the carrying member, on whichauxiliary plates the carrying member can be fastened.

Even if the shaft itself is secured to the carrying member in anon-rotatable manner it is possible to cover a large working area withthe platform, for instance by so designing the platform that it rotatesabout the fixed shaft. The suspended working platform unit shown in thedrawing is to be preferred, however, as it is very simple and effectivein use and can be cheaply manufactured. 7

I claim as my invention:

1. A rotatable suspended Working platform supported solely from a singleoverhead carrying member and adapted for use in closed tank structuresthat have at least one access opening in the top thereof, comprising:

(a) a vertical support shaft; (11) a carrying member having means forrigid attach- 5 ment to the tank at said access opening, for suspendingsaid shaft for rotation about a vertical axis;

(0) a horizontal plate surrounding the shaft and positioned in supportedrelation to said carrying member, said plate being movable with respectto the shaft, and a horizontal rod inserted transversely through to thetop part of the shaft and connected to said plate in supported relation,whereby the shaft can be lowered from the carrying member by slidingthrough said plate after removal of the rod;

(d) a rigid platform pivotally secured directly to the lower portion ofsaid shaft to one side thereof for movement about a horizontal axis,whereby said platform, with the shaft pivotally attached, can passthrough a narrow opening when the platform is pivoted upwardly; and

(e) means to interconnect said platform and shaft into a rigid unitwherein said platform is substantially horizontal.

2. A platform as defined in claim 1 wherein the said plate carries meansfixing the plate to the shaft against relative rotation, said platebeing rotatable with respect to the carrying member, and a detachablefastener for securing said plate and carrying member against relativerotation in selected angular positions of the shaft.

References Cited by the Examiner UNITED STATES PATENTS 686,159 11/01Sprague 182121 812,620 2/06 Alstine 182-121 1,864,934 6/32 Reeves182-428 2,575,503 11/51 Warren 182150 2,697,776 12/54 Wale 2482913,033,389 5/62 Abarotin 182-150 40 HARRISON R. MOSELEY, PrimaryExaminer.

1. A ROTATABLE SUSPENDED WORKING PLATFORM SUPPORTED SOLELY FROM A SINGLEOVERHEAD CARRYING MEMBER AND ADAPTED FOR USE IN CLOSED TANK STRUCTURESTHAT HAVE AT LEAST ONE ACCESS OPENING IN THE TOP THEREOF, COMPRISING:(A) A VERTICAL SUPPORT SHAFT; (B) A CARRYING MEMBER HAVING MEANS FORRIGID ATTACHMENT TO THE TANK AT SAID ACCESS OPENING, FOR SUSPENDING SAIDSHAFT FOR ROTATION ABOUT A VERTICAL AXIS; (C) A HORIZONTAL PLATESURROUNDING THE SHAFT AND POSITIONED IN SUPPORTED RELATION TO SAIDCARRYING MEMBER, SAID PLATE BEING MOVABLE WITH RESPECT TO THE SHAFT, ANDA HORIZONTAL ROD INSERTED TRANSVERSELY THROUGH TO THE TOP PART OF THESHAFT AND CONNECTED TO SAID PLATE IN SUPPORTED RELATION, WHEREBY THESHAFT CAN BE LOWERED FROM THE CARRYING MEMBER BY SLIDING THROUGH SAIDPLATE AFTER REMOVAL OF THE ROD; (A) A RIGID PLATFORM PIVOTALLY SECUREDDIRECTLY TO THE LOWER PORTION OF SAID SHAFT TO ONE SIDE THEREOF FORMOVEMENT ABOUT A HORIZONTAL AXIS, WHEREBY SAID PLATFORM, WITH THE SHAFTPIVOTALLY ATTACHED, CAN PASS THROUGH A NARROW OPENING WHEN THE PLATFORMIS PIVOTED UPWARDLY; AND (E) MEANS TO INTERCONNECT SAID PLATFORM ANDSHAFT INTO A RIGID UNIT WHEREIN SAID PLATFORM IS SUBSTANTIALLYHORIZONTAL.